Improve spacing and alignment in the Windows UI #122

While using Flock on Windows, I noticed few small UI issues that make some screens feel uneven. I'd like to contribute a few visual fixes to make the app feel more consistent and comfortable to use.

The changes cover:

• Alignment of labels, switches, and status values.
• Spacing around settings headings, service cards, and scrollbars.
• A clearer All / Installed selector.
• Adjusted title-bar height and clearer close, maximize, and minimize buttons in light mode.
• The missing logo on the About page.
• Dropdown menus that stay within the window and have a solid background so the content behind them does not show through.
• Fix Modal Button Colour

The build and tests pass. I've also checked light and dark mode, filtering, menus, and keyboard navigation.

Before and after

Area	Before	After
Tray menu
Settings
Services
About page (light mode)
Modal

Note: I've kept these in one PR because they are small, related visual fixes. Reviewing them together should be easier than opening a separate PR for each spacing or alignment change.